"Le Monde newspaper called the museum's construction the 'rape of Paris,' and city politicians thought their money had been totally wasted," said Lasvignes. The 10-floor museum required 15,000 tons of steel and cost millions to build. Critics said it looked like an oil refinery.

France's first museum entirely devoted to contemporary art saw the light of day thanks to the obstinacy of one man — Georges Pompidou, an art lover who served as France's president from 1969 to 1974 and prime minister from 1962 to 1968.

"Pompidou thought there was a real gap at the time between the progressiveness of French industry and the country's conservatism when it came to cultural matters," said Lasvignes. "And he thought that gap partially explained the social explosion and student revolts of 1968." Pompidou was widely credited for resolving those revolts when he served as prime minister.

In 1971, Pompidou launched an international competition to build the museum, originally known as the Centre Beaubourg. "The idea was to have a complex for contemporary art and with new architecture," said Lasvignes.

The winning team, which included three young architects from Britain and Italy, was completely unknown at the time. Renzo Piano and Richard Rogers, the two architects who saw the project through, made their provocative plan a reality, putting the museum's working guts — its plumbing and electricity — on the outside, to leave more space inside for art.

Their design took everyone by surprise.

"They didn't think they had a chance to win," Lasvignes said. "So they thought they might as well do exactly what they wanted and be entirely original."

But there was a real philosophy behind their design, he said.

"Someone said to Piano, 'Your thing is horrible — with the escalator on the outside, it looks like a supermarket!' And Piano replied, 'Well, that makes me happy, because it means no one will be too intimidated to come inside.'"

Forty years later, the museum still strives to make culture accessible to everyone, Lasvigne said. He calls the Pompidou Center a museum like no other.

"Our mission is pluri-disciplinary, so we are not only a museum," he said. "We have concerts, debates, performances, a library ... and everything flows together."

Pompidou felt putting up walls between different forms of art — compartmentalizing it — was detrimental.

"So we are a house of culture where people return again and again," Lasvignes said. "Most of our visitors come more than once a year, which is different from other Paris museums."

After the 2015 terrorist attacks in Paris, Lasvignes said the Pompidou Center was the only museum in the city where the number of visitors actually increased. The museum received 3.3 million visitors in 2016, a 9 percent increase over 2015.

"Many Parisians refused to stay home and wanted to continue to live after the attacks," he said.

Some 60 percent of the Pompidou's visitors are French. Lasvignes calls it the "museum of Parisians." At the Louvre, in contrast, almost 70 percent of visitors are foreign.

The Pompidou Center is Europe's biggest modern art museum; New York's Museum of Modern Art is the biggest in the world. But the two museums have totally different strategies, Lasvignes said.

"The MOMA's strategy is to collect masterpieces, and we try to represent an entire epoch," Lasvignes explained. "For example, we have an incredible surrealist collection. They're not all masterpieces, but it's a complete collection and you can see the nuances."

Lasvignes said that's how the Pompidou Center was able to stage a recent exhibition on surrealism in Egypt.

"No one even knew [surrealism in Egypt] existed!" he said.

Lasvignes said visitors to the Pompidou experience an exhibit in a way that's entirely different than at other museums.

"We find an original angle of attack and the works are displayed differently. They're often accompanied by music or literature. It's like an unexpected trip. And this is what attracts people," he said.

To highlight the work of Swiss-German expressionist artist Paul Klee, who Lasvignes said some may be a bit tired of, the Pompidou mounted an exhibit highlighting irony and humor in Klee's work, something Lasvignes described as "a totally new itinerary that helped people rediscover Paul Klee."

Nadine de Grandsaigne, visiting the Pompidou Center from the Paris suburbs on a crowded winter day, says she comes back again and again. She says the Louvre is too big.

"And," she says, "I love the view here."

Visitors who ride the escalator to the top of the museum are rewarded with a panoramic view of Paris. Particularly visible are the hill of Montmartre and the white domes of the Sacré Coeur church.

Grandsaigne says she remembers the uproar when the museum first opened. While she liked it, she feared it would become ugly with time.

"But it doesn't get old," she says. "It is still exceptional."

Now that it's 40, the Pompidou's goal is to continue to cultivate originality and remain cutting-edge, Lasvignes said.

"We want to be in tune with the intellectual tendencies and international currents of 2017," he said, "and not become a conservatory of nostalgia and history."

Lasvignes said the Pompidou Center will remain "a safe place for unsafe ideas."

With a presidential election this spring, and far-right populist leader Marine Le Pen currently in the lead, Lasvignes mentioned no names but said his museum could take on "an activist role."

"We are not involved in politics," he said. "But we recognize that sometimes culture needs to be pushed to avoid a sclerosis of society."

Access to culture and art is crucial to opening minds and learning how to deal with what's different and foreign, he said. If there were to be any attempt in France to shut people's minds and break the bridges between cultures, "Then yes," he said, "the Pompidou Center would step in to play a role of resistance."